'Overlapping surgeries' linked to increased risk of complications

The risk of complications for hip replacements rose from 1.4 percent to 2.3 percent when the operations overlapped, while the risk for hip fracture surgery rose from 6.4 percent to 10.4 percent.

The controversy regarding overlapping surgery — the practice of some surgeons to be involved in more than one operation at the same time — intensified Monday.

A new Canadian study, published in JAMA Internal Medicine, reported that patients undergoing hip surgery were twice as likely to experience serious complications if their operation was “double-booked” by their surgeons.

The longer the surgeries overlapped, the greater the risk, the study also found.

Overlapping surgeries first hit the headlines in 2015, when a Boston Globe investigative report of the practice at a Boston hospital raised safety concerns. Since then, several studies have looked at the issue, and most have found that overlapping surgeries have no impact on complication rates.

Indeed, a study published just last month in JAMA Surgery reported that although overlapping neurosurgeries tended to be “significantly longer” — a factor that meant the patients often spent more time under anesthesia — they were not associated with a higher complication rate.

The current study, however, is much larger than the previous ones. It examined data from more than 90,000 hip operations at about 75 hospitals. It also followed patients for up to a year rather than a few weeks.

Study details

The new study focused on hip surgery patients — people who underwent either hip replacements or surgery for hip fractures in Ontario, Canada, from 2009 through 2014. Because these patients tend to be older, they are at greater risk of surgery-related complications than patients in some of the other studies that investigated overlapping surgery. (The mean age was 66 for the hip replacement patients in the current study and 84 for the hip fracture patients.)

The study found that overlapping surgery was relatively uncommon. Of the 38,008 hip fracture surgeries in the study, only 960 (2.5 percent) were overlapping. Of the 52,869 hip replacement surgeries, only 1,560 (3.0 percent) were overlapping.

But the data also found that overlapping surgery was associated with an increased risk of surgical complications. If a surgeon was supervising two operations for as little as 30 minutes, the complication rate climbed by 80 to 90 percent. The association was strongest for overlapping hip fracture operations. In those cases, the risk rose 7 percent for every 10 minutes that the operations overlapped.

Still, in absolute terms the increased risk was modest. The risk of complications for hip replacements rose from 1.4 percent to 2.3 percent when the operations overlapped, while the risk for hip fracture surgery rose from 6.4 percent to 10.4 percent.

Need for transparency

“This seems to be the first study to show an adverse effect from the practice of overlapping surgery,” writes Dr. Alan Zhang, an orthopedic surgeon at the University of California San Francisco, in a commentary accompanying the study. “The increased length of follow-up is an important factor to consider for complications, which adds value to the results of the current study.”

Zhang says the findings underscore the need for surgeons to be transparent with their patients about the practice of overlapping surgeries.

“If given full disclosure by the surgeon, some patients may be adverse to having their surgery overlap while others ambivalent, but informed consent should be necessary for all,” he writes.

But critics of the practice say it should be ended.

“This study shuts the door on the idea that simultaneous surgery is as safe as solo surgery, when the doctor’s just concentrating on you,” Dr. James Rickert, an Indiana orthopedic surgeon and president of the Society for Patient Centered Orthopedics, told Boston Globe reporter Jonathan Saltzman. “The size, the numbers, the multiple institutions, and the long-term follow-up dwarf any of those other studies.”

Dr. L. D. Britt, a past president of the American College of Surgeons who heads the department of surgery at Eastern Virginia Medical School, was equally critical of the practice, telling the Globe that surgeries should be allowed to overlap for only a brief period at the end of one of the operations and the beginning of the other.

“Attempting to validate concurrent operations by documenting safe outcomes is tantamount to my blindfolding my daughter and having her walk across a busy six-lane highway,” he said. “Just because she might reach the other side safely does not dictate a best practice.”

FMI: Abstracts of the study and the accompanying commentary can be found on the JAMA Internal Medicine website, but the full papers are behind a paywall.